1. Field of the Invention
The present invention relates to an electrical connector, and more particularly to a ZIF (Zero Insertion Force) socket connector for connecting a central processing unit (CPU) of a computer system to a printed circuit board (PCB).
2. Description of Related Art
With the development of technology, socket connectors, which have pins or solder balls, are found widespread applications in computers and other electrical devices for transmitting signals and conducting current between a printed circuit board (PCB) and an IC package.
Referring to FIGS. 1–2, a conventional socket connector 9 comprises a base 91, a cover 93 slidably mounted on the base 91 and a lever 94 sandwiched between the base 91 and the cover 93. The lever 94 includes a cam shaft 944 received in the base 91 and an operating handle 940 vertically extending from the cam shaft 944. The base 91 defines a mating portion 910 with a plurality of passageways 914 vertically extending through a top and a bottom faces for receiving a plurality of terminals 92 therein, and a header portion 912 having a channel 911 extending along a lateral direction. A pair of protrusions 916 is formed on opposite side of the mating portion 910. The cover 93 includes a mating portion 930 for mating with an IC package (not shown). The mating portion 930 defines a plurality of passageways 934 in alignment with the passageways 914 for allowing downwardly extending pins of an IC package (not show) to extend therthrough to engage with the terminals 92. A pair of side walls downwardly extending from opposite ends of the mating portion 930 with a pair of slot 936 formed thereon. The cover 93 further includes a header portion 932 having a channel 931 extending along a lateral direction. A pair of locking barbs 938 are extending downwardly from the header portion 932 adjacent to the channel 931 alignment with corresponding portion of the base 91.
In assembly, the cover 93 movably mounted on the base 91, the terminals 92 is received in the passageways 914 of the base 91 and the lever 94 is sandwiched between the base 91 and the cover 93. The cover 93 can slide on the base 91 by actuating the lever 94 from a vertical position to a horizontal position, which makes pins of the IC package move simultaneously for establishing/disestablishing an electrical connection between the pins of the IC package and mating portions of the terminals 92. It is noted the steady electrical connection between the IC package and the PCB is deeply affected by the plainness between the cover and the base.
As the base 91 and the cover 93 is conventionally made from insulative materials by molded, and they should be made thin enough, they are apt to warp in molding or cooling process. When the warped base or cover are assembled, the header portions of the socket are fastened tightly enough by the engagement of the barbs 938 with the base, and the mating portions also can be engaged tightly by the engagement of the protrusions 916 with the slots 936. But the warp of the socket will make a rear portion of the socket to form an aperture, and make the contacts 92 in the rear portion touch dust out of the socket. Furthermore the warp of the socket make the passageways 934 can not alignment with the passageways 914 respectively, and the terminal 92 cannot contact the pins of the IC package steadily.
To overcome above-motioned problems, an improved socket connector is desired.